Lovebirds Russell Brand and Katy Perry are having bitter rows about their wedding plans.

A source close to comedian Brand and his American singer fiancée ­revealed: “They couldn’t have more different ideas about things.”

HE wants them to celebrate their big day with a fun Victorian-themed ­costume party – then have a baby as soon as possible.

SHE wants to please her ultra-­conservative preacher parents with a Christian ceremony in her native ­southern California – and wait to start a family.

The source said: “Katy wants a church wedding. Russell wants something more wacky and new age.

“They can’t even decide the basics – like where to have the wedding and who to invite. Now they are arguing about it all.”

The pair, who got engaged in January, are also having trouble fixing a date. Babies are the other sore point.

Reformed sex addict Brand, 34, is said to be desperate to start a family.

But I Kissed A Girl star Katy, 25, is too busy with her ­career to think of getting pregnant.

The source said: “Katy has so much on. Her new album is scheduled for release this summer and a tour is likely to ­follow. She is also interested in branching out into acting so she can’t even consider being a housewife or raising kids just yet.

“She doesn’t want to even think about having a baby for at least another year but Russell would be happy if Katy got pregnant right now.”

Katy seems to have made up her mind on one aspect of the wedding – friends say she wants pop star pal Rihanna to be one of her bridesmaids.

Brand proposed to Katy in India on New Year’s Eve after just three and a half months of dating.

He has met her parents Mary and Keith Hudson, who declared: “He’s won us over. He’s part of the family.”

Brand and Katy seemed to have put their differences to one side last week as they relaxed in Mexico.

Party

Russell could hardly take his eyes off his fiancée as she nearly burst out of her skimpy red bikini in the resort of Cabo San Lucas.

Katy didn’t seem worried by reports that Brand had gone back to his old ways after he was spotted at a pre-Oscars party pinging the elastic on a girl’s fishnets and laughing flirtatiously.

She seemed more ­bothered by Russell ­becoming ­obsessed with the wedding arrangements.

Katy said: “He’s a total b­ridezilla. He’s like a freak, man.

“You should see him – he’s always, like, buying bride magazines.

“Every time we go out for breakfast he’s like, ‘Can we just stop and get a bride magazine?’”